Hi Miguel,
Here's a bit more information. There is no support in McLachlan for using LegoExcision. LegoExcision was used with an old implementation of BSSN. As Jonah said, when using Llama, it's possible to do excision by using a six-patch coordinate setup. In principle it is also possible to use a patch system with 13 patches to have 2 spherical exicision regions. However, there is no infrastructure for keeping 2 black holes centered on the excision regions as the system starts to evolve. Hence, you'll encounter the problem that the black holes will move and the excision regions will eventually cross the horizon at which point your simulation will crash.
To perform simulations a lot of infrastructure (a la what is available in SpEC) to control the shape and size of the horizons during a dynamical evolution.
Cheers,
Peter
On Monday 2017-03-27 09:59, Jonah Miller wrote:
Date: Mon, 27 Mar 2017 09:59:51 From: Jonah Miller jonah.maxwell.miller@gmail.com To: users@einsteintoolkit.org Subject: Re: [Users] Excision with McLachlan
Hi Miguel,
I'm not sure about excising dynamically during evolution--maybe someone else has insight there. However, excision is definitely possible. I have been using the sixpatches Llama thorn to perform excision for a single black hole. I attach a parameter file to excise a Kerr-Schild black hole that I based my simulations on.
Best,
Jonah
On 2017-03-27 05:01 AM, Miguel Zilhão wrote:
hi all,
i was wondering whether one could straightforwardly use the ET to perform black hole evolutions using excision instead of punctures.
specifically, i had in mind a collapsing configuration where i'd like to excise the inner domain once a black hole horizon is formed... is this possible? i had a look around and noticed the LegoExcision thorn, but i'm not sure whether it's actively maintained, nor whether it can interface with McLachlan...
thanks, Miguel _______________________________________________ Users mailing list Users@einsteintoolkit.org http://lists.einsteintoolkit.org/mailman/listinfo/users